Plastic material and composite accelerating material therefor.



106. COMPOSITIONS,

COATING R PLASTIC. l

UNITED 'STATES PATENT OFFICE.

EDWARD L. CONWELL, 0F UPLAND, PENNSYLVANIA, 'ASSIGNOR TO ALUMINATE PATENTS COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

PLASTIC MATERIAL AND COMPOSITE ACCELERATING- MATERIAL THEREFOR.

No Drawing.

as 151 ral. Rosendale or Roman cement and also supersulfate or other available energizing material such as bisulfatesor disulfates of the alkali meta l s.

1e invention relates especially to plaster compositions of this character comprising la rge proportions of h drated lim mixdwi'th"arel'ativeTyEiimW mun-a1 cement fraaema nate: rut W1 i no i "gm-and together or otherwise mixed sodium disulfate eue gl z ing nia; terial or the 1 to so 1a ie plaster composi tioii s, that is compositions used for wall plas:

tering and the like and also in some cases useful as mortars for brick laying and so forth, are improved in working properties such as plasticity, reliability, sand-carrying and cementitious properties, especially if somewhat large proportions of the composite strength accelerating material are incorporated.

The invention also relates to such combined strength accelerating material comprising natural cement and cooperating en ergizing material such as sodium disulfate or the like. Suitable energizing materials of this class, that is, compounds apparently having loosely combined or otherwise available sulfuric acid or sulfuric anhydrid aifl ivifim arearerenrreferreu "tB a s S'uperSulfates, such for example, as )otassium disul fate !K S,O,2 or its more hydrous variant p0 assium isulfate KHSO sodium disu ae la, 2 7 ie reaed so mm 1- su a e NaHSOQ, ammonium bisulfa ZNH PLSOQ, ferric su a e e, and acid calcium sulfate. preferably in their 0r cru e orms such as niter commercia l Specification of Letters Patent.

Patented June 6, 1916.

Application filed November 7, 1912. Serial No. 729,979.

cake ac i d 1 '1 atensln e and so m seem o iave esira e energizing action on natural cement strength accelerating or hardening material when incorporated therewith, so as to increase and hasten the strength accelerating and CGII'IBlHtltlOHS action of such material on cooperating cementitious material comprising hydrated or otherwise available lime. This seems to be due to the supersulfate energizing material acting upon and disintegrating or opening up the strength accelerating material, possibly because of its available loosely combined sulfuric anhydrid, either with or without water united therewith, thus apparently promoting the activity of certain hydraulic elements and their solubility inalkaline solutions of the material present, or rendering them more active in connection with the lime component of the cooperating cementitious material. Such supersulfate energizing material when incorporated to the extent of a few per cent. more or less, for example, with wall plaster compositions comprising about 85 parts of hydrated lime and 15 to 25 parts or so of natural cement, materially promotes the cementitious propertiesand hydraulic set of the plastic composition and makes' tne compositions more desirable for use, especially under extreme service, where for example, conditions tend to promote excessive drying out. Many such cooperating energizing materials containing similarly available loosely combined sulfuric anhydrid or sulfuric acid not only increase the cementitious properties and early strengths of the plastic compositions, but also promote their plasticity, reliability and spreading properties and their hardening and substantially uniform homogeneous setting.

It is desirable that the natural cement strength accelerating material and the sodium bisulfate or other energizing mate rial containing available acid should be |1d toetle or otherwise thoroughly inw ec v 1 seems to pi'mmitiation of chemical action to the extent permitted by the presence of the usual small proportion of Water therein, and the opening up or disintegration of the strength acceler 10.2% N T-Q its...

sat sfactory from the practical ating material. The strength accelerating action occurring when the plaster compositions or other calcareous cementitious materials in which such prepared materials are incorporated, are gaged and tempered, is possibly increased because of the further chemical interaction of the acid and other components and the decomposition or liberation of the aluminous, silicious or other hydraulic components in such form as to more readily exert cementitious or hydraulic action in connection with the lime and so forth. Besides securing an extremely intimate and desirable incorporation of the natural cement and any suitable cooperating energizing material containing loosely combined or available sulfuric anhydrid, this method of incorporation by grinding these components together, in ball and tube mills, for instance, also produces desirable combined strength accelerating materials which may be produced and shipped in the dry finely divided condition suitable for mixture in desired proportions with hydrated lime or other cooperating calcareous cementitious material. Hydrated lime plaster compositions prepared in this way by the incorporation of ten to thirty per cent. or so of suitable natural cemenT stlen tTi acceleratworking standpoint, and possess to a considerable extent many of the desirable features of ordinary lump lime putty plasters including plasticity, ease of working and large sand carrying properties, besides being much more convenient to prepare for use, quicker hardening and having greater early strengths and cementitious or hydraulic properties and being more durable and resistant to weather conditions. Such supersulfate energizing material may be advantageously mixed or incorporated in any desired way, preferably by grinding or otherwise intimately mixing with any suitable natural cement and with various cooperating cementitious materials comprising free or available lime, such for example, as with hydrated lime wall plaster compositions containing large proportions of lime, in the case of hydrated lime plaster compositions the lime and strength accelerating and energizing materials may with advantage be crushed together or intimately incorporated and the compositions simultaneously densified as described at length and claimed in the application of Spackman and Lazell, Serial No. 698,906, filed May 22, 1912. For general purposes good results are secured when sufiicient sodium disulfate or bisulfate is incorporated so that free or available sulfuric acid s thus pgovi e 0 1e exten t 0 .320 to .5 or so of the total h drated lime coi'n positioh containing lo?!) to 20% more or ess 0 1e natural cement strength accelerating material.

A plaster composition was made by incorporating with dolomitic hydrated lime 15% of the composite strength accelerating material comprisin natural cement ground together with one-elghth as much sodium disulfate which produces a composition having good workability and spreading properties and desirable hardening and early strengths so as to be much superior to a corresponding mixture of the natural cement and lime without the incorporation of the supersulfate energizing material. This composition when one part was tested with four parts of Ottawa sand gave the following tensile strengths per square inch: at 24 hours 7 pounds, at 2 days 22 pounds, at 7 days 27 pounds, at 28 days 32 pounds, at 3 months 62 pounds, the magnesian hydrated lime, the combined strength accelerating material comprising natural cement and sodium disulfate, and the sodium disulfate energizing material used in the foregoing composition having about the following analyses:

Natural cement: (It 0 m k i n e 51 s renxrt acce gg crating material Sodium hvdmted comprising 8 disul 8 parts natural cefate ment and 1 part sodium disulfate.

Silica (SiOg) 2. 04% 26. 92% 1. 5% Ferric oxid and alumina (R 0 0.64 10.84 0.2 Lime (CaO) 44. 35 Magnesia (MgO) 30. 86 2. 84 Calcium carbonate (CaCOg). 3. 32 Calcium hydrate (Ca(OH) 61. 58 Sodium sulfate (N82SO4) 62. 8 Sulfuric anhydrid (803).... 7. 40 30.1 Mech. contained water. 24 Water (H O) 5. 3 Loss on ignition 5.16

Another suitable plaster composition was produced by thoroughly incorporating with hydrated high calcium lime 15% of the composite strength accelerating material comprising natural cement and one-eighth as much of sodium disulfate which had been ground together with the natural cement so as to be thoroughly incorporated. This plaster composition gave when similarly tested the following tensile strengths: at 24 hours 30 pounds; at 2 days 56 pounds; at 7 days 62 pounds; at 28 days 82 pounds, this natural cement being designated No. 1 in the following table. Another suitable plaster composition which had somewhat less satisfactory hardening properties when used as a wall plaster was made by similarly incorporating with the same high calcium hydrated lime 15% of similar composite strength accelerating material formed by grinding together 1 part of sodium disul- 106. COMPOSITIONS,

COATING OR PLASTIC.

fate with 8 parts of another natural cement designated No. 2 in the following table. This plaster. composition when similarly tested gave the following tensile strengths: at 24 hours 10 pounds; at 2 days 35 pounds; at 7 days 43 pounds and at 28 days 58 pounds.

Natural ce- Natural cement #2.

It is of course understood that the strength tests given in connection with the foregoing examples must be considered in connection with the extreme difficulty of securing reliable strength tests with lime plaster compositions. These tensile tests were made on briquets formed in the regular way for cement testing, the briquets being kept in air, but in spite of all possible precautions considerable variations are likely to be found in such results and it is well understood that much more reliance must be placed on the practical working results of such plaster compositions in which way their plasticity, sand carrying qualities, workability and hardening, setting, strength and reliability can be determined in a more satisfactory way, especially since high tensile strengths are not of first importance in ordinary plastering compositions,provided the material develops at a relatively early period suflicient strength to certainly remain in position on the wall in spite of such disturbance or vibration as may be occasioned by setting the adjacent door frames or trim.

The invention has been described in connection with a number of illustrative compositions, ingredients, proportions, formu-- las and methods of preparation and use, to the details of which disclosure the invention is not of course to be limited, but

What is claimed as new and what is desired to be secured by Letters Patent is set forth in the appended claims.

1. The plaster composition comprising a large proportion of high calcium hydrated lime mixed with ten to thirty per cent. of natural cement which has been ground together with about five to fifteen per cent. as much sodium disulfate energizing material.

2. The plaster composition comprising a large proportion of hydrated lime mixed with natural cement which has been ground together with alkali metal supersulfate energizing material.

3. The plaster composition comprising a large proportion of hydrated lime mixed with natural cement and about five to fifteen per cent. as much alkali metal supersulfate energizing material.

4. The plaster composition comprising a large proportion of hydrated lime mixed with natural cement and alkali metal supersulfate energizing material.

5. The plaster composition comprising a large proportion of hydrated lime mixed with natural cement and supersulfate energizing material.

6. The plaster composition comprising a large proportion of available lime mixed with natural cement and energizing mate- LAdt-Hllii rial comprising available sulfuric anhydrid loosely held in combination.

7. The plaster composition comprising a considerable proportion of available lime mixed with natural cement which has been ground together with about 5 to 15 per cent. of supersulfate energizing material.

8. The plastic composition comprising a considerable proportion of available lime mixed with natural cement and alkali metal supersulfate energizing material.

9. The plastic composition comprising a considerable proportion of available lime mixed with about ten to thirty per cent. of natural cement which has been ground together with supersulfate energizing material comprising available sulfuric anhydrid loosely held in combination.

10. The plastic composition comprising a considerable proportion of available lime mixed with about ten to thirty per cent. of natural cement and about five to fifteen per cent. as much cooperating supersulfate energizing material.

11. The plastic composition comprising a considerable proportion of available lime mixed with about ten to thirty per cent. of

.natural cement and about one-eighth as much cooperating energizing material comprising available sulfuric anhydrid loosely held in combination.

12. The plaster composition comprising a large proportion of available lime mixed with about 10 to thirty per cent. of natural 5 to 15 per cent. as much alkali metal supering available sulfuric anhydrid loosely held in combination.

18. The substantially dry composite strength accelerating material capable when incorporated therewith of improving working properties of hydrated lime plaster compositions and comprising natural cement intimately mixed with a relatively small amount of sodium disulfate energizing material.

EDWARD CONWELL.

Witnesses:

BENJAMIN H. LuDLoW, WILLIAM H. CREAMER, Jr.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0." 

